Generally, a fuel-cell hybrid electric vehicle simultaneously uses a low voltage power source, e.g., a fuel cell, and a high voltage source, e.g., a battery, in order to increase power efficiency and to obtain a stable power supply for operating the vehicle. Fuel-cell hybrid electric vehicles also include a bi-directional DC/DC converter that is coupled both to the fuel-cell and to the battery. The bi-directional DC/DC converter includes a plurality of switching units and diodes, and controls power conversion between the fuel-cell and the battery.
The bi-directional DC/DC converter is configured to perform a buck operation or a boost operation. During the buck operation, power is transmitted from the battery to the fuel-cell, and during the boost operation, power is transmitted from the fuel-cell to the battery. During these operations, an arm-short may occur in the bi-directional DC/DC converter, and the arm-short may cause abnormally huge current flows that can damage the converter as well as the battery and the fuel-cell. It is therefore useful to prevent such an arm-short, and to immediately detect an arm-short to secure normal operation of the bi-directional DC/DC converter.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.